PLATE IV. 



PAGE. 



Figs. 1 to 7. PHYLLOPORINA SUBLAXA, Ulr 209 



1 and 2. Reverse side of small fragment, natural size and portion of same *9, showing 

 striated character of this side in young or exfoliated examples. Lower Trenton lime- 

 stone, Minneapolis, Minn. Survey Museum. Reg. No. 5954. 



3 and 4. Another fragment from the same locality, exposing the obverse side, natural size, 

 and portion of same x9. 



5. Tangential section, xis, showing appearance of zooecia at varying depths. 



6. Two transverse sections of branches, *18. 



7. A rather loosely woven frond from the "Glade" limestone at Lavergne, Tenn.; natural size. 







Figs. 8 to 14. PHYLLOPOKINA KETICULATA (Hall) 210 



8. A frond exposing the reverse side, natural size, Minneapolis, Minn. 



9. Portion of same, xg. 



10 and 11. Another fragment from the same locality, natural size and *9. 

 12. Small fragment, likewise from Minneapolis, exposing the obverse face, xis. 

 13 and 14. Obverse and reverse sides of two fragments obtained from washings of Galena 

 shale at Cannon Falls, Minn.; xis. 



15. Tangential section, xis, of an example from Trenton Falls, N. Y. 



Figs. 16 to 21. PHYLLOPORINA HALLI Ulr 211 



16. Reverse side of a specimen, natural size, showing irregular arrangement of fenestrules. 



17. Celluliferous side of another fragment, natural size, showing the irregular solid swellings. 



18. Surface of same, xg. 



19. Reverse side of same, xg. 



20. Tangential secti6n, xis, cutting the zooecia just beneath their mouths. 



21. Another portion of same section, xis, where it divides the zoarium at a deeper level. 

 Upper third of the Trenton shales at St. Paul, Minn. 



